How do you say: "Oh very funny." " Oh, very funny."

Question

How do you say:    "Oh very funny."  >>> " Oh, very funny."

Answer

I'll give you some expressions more natural & more usable,

1.웃기고 자빠졌네 - (Literally) He makes me laugh & falling down on the floor  
                                 (Colloquially) It's funny, but lame

2.웃기고 앉아있네 - (Literally) He makes me laugh & sitting down on the floor
                                 (Colloquially) It's funny, but lame(less than the above)

3.웃기고 있네 - just same, but not very funny , still lame though

You can regard 'rofl' , but it's totally opposite as the person who falls down makes someone laugh

Answer

If its meaning is stuck in between 'good joke' and sarcasm, I'd say '오, 좀 웃기네'. 좀 means kind of, sort of etc.  

You could pick up what 박정현 said, but it should be 그래, 웃긴다 웃겨~!.

웃기다 is an action verb that means 'to make someone(me in this case) laugh', it doesn't make any sense because it's a basic form found in dictionaries. 

Hope it helps!

Answer

그래, 웃기다 웃겨~!  would be fit to that situation as usual expression.  
as for more tips for that expression, if you use the word like "freaking or hell" or sentense(in korean) which is something extreme emphasis expression more than times of it is supposed to be used, it means not "they meant to say", the opposite of the meaning.